47 V8 ignition mystery

[Old Henry]

Originally Posted by Ggmac

I wish you a safe and productive and rewarding trip .

Thanks. I believe that we will have all of that and more.

(Congratulations! Your post was the 200th of this thread that was thought would never end. Maybe now it can.)

[Mart]

I don't know what others may think, but it might be worth holding the clutch pedal down to try and avoid clutch plate getting stuck. Or ask your son to not only start it up but engage forward and reverse gears and let the clutch almost bite.

Have a productive and rewarding mission trip.

Mart.

[cas3]

Mart, while its a good thought to protect the clutch disk, I believe its not a problem with the nice dry air in Utah.

[flatford8]

Have a safe journey Craig!…….Mark

[corvette8n]

I put mine on jackstands when it’s put away for winter 4-5 months.

[Terry,OH]

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Did you check for a vacuum leak on the vacuum line at the distributor and on the end at the intake manifold, where there is a special bolt connecting the vacuum line to the intake, the special bolt can break, or be loose or the banjo type fitting can be leaking on either side. The rubber tube to the vacuum wipers may be cracked, best to block the vacuum port at the point where the wiper tube connects to check. If your connecting to the wiper port on the special bolt with your vacuum gauge then the wiper rubber tube is not the problem.

Check for a leak where the distributor mounts to the timing cover. There should be a special rubber O-ring at the rear of the distributor that seals the vacuum to the distributor vacuum brake.

[petehoovie]

Originally Posted by Terry,OH

Did you check for a vacuum leak on the vacuum line at the distributor and on the end at the intake manifold, where there is a special bolt connecting the vacuum line to the intake, the special bolt can break, or be loose or the banjo type fitting can be leaking on either side. The rubber tube to the vacuum wipers may be cracked, best to block the vacuum port at the point where the wiper tube connects to check. If your connecting to the wiper port on the special bolt with your vacuum gauge then the wiper rubber tube is not the problem.

Check for a leak where the distributor mounts to the timing cover. There should be a special rubber O-ring at the rear of the distributor that seals the vacuum to the distributor vacuum brake.

[Old Henry]

Gentlemen,

I'm back from 22 glorious months in the Philippines serving my Lord and Savior, Jesus Christ.

I was hoping that having 22 months to rest and sleep would have healed Old Henry of his chronic cough. I was pleased that, in fact, he did seem cured . . . for just a few days . . . before he started coughing again.

In the last month I've read and reread all 207 posts received from all of you good friends to try to help me cure him and tried a few of the same things again I've already done without any success.

Just to review, here is my summary of everything I did before I left two years ago and since returning:

1. Replaced the battery.
2. Rebuilt carburetor including replacing accelerator pump.
3. Replaced all spark plugs with Autolite 216 gapped at .25.
4. Replaced distributor with Ford remanufactured one from Southside Obsolete.
5. Put new points in the distributor.
6. Replaced the condenser checked at .32 mfd at 160 degrees
7. Replaced all spark plug wires and converted from rabbit ears to crab cap.
8. Replaced the coil.
9. Jumped from battery to coil bypassing ignition switch and resistor. Made it worse.
10. Checked all grounds from battery to firewall to head bolt. All OK.
11. Checked generator charging voltage. It’s 6.8 volts.
12. Replaced the distributor rotor.
13. Replaced distributor cap gasket to make sure seated squarely. No change
14. Checked for spark plug wire leaks/shorts in the dark. Aren’t any.
15. Checked for water hitting dizzy from leaky water pumps. None.
16. Checked all cylinder compression. All between 90 and 100.
17. Ran without air cleaner. Didn’t help.
18. Been running MMO. No improvement.
19. Vacuum test was quite low and bouncy suggesting late valve timing. Don’t know how that could be on one cylinder. Checked for vacuum leaks around carb and intake manifold. Found none.

Current symptoms are:
1. Cylinder #6 mostly not firing at all. (I'm not focusing on that right now. I can do without that cylinder if I can get all others working right.)
2. All other cylinders firing fine until gas pedal depressed even so slightly.

My last test was to hook up my timing light to the coil HT line and place the light on my cowl so I could watch it while driving. It was steady, along with all cylinders (except #6) firing until I moved the gas pedal down in any amount. Then, immediately, the light would go erratic along with the cylinders misfiring until I let the gas pedal up to level cruising speed. It almost seemed like the sudden erratic firing was connected some way to reduction of vacuum.

Is that possible? If so, how and what to do about it?

[ford38v8]

Henry! So glad to have you back! We’ve missed you more than you know.
The following items may indirectly affect your ongoing problems:
Your coil may need replacement by a Skip Haney rebuild, as you say bypassing the resistor makes the miss worse. The bypass, by the way, should only be during the use of the starter motor.
The erratic miss at acceleration may be due to the advance disc movement or non- movement, and also, its relationship to any protruding terminal screws that could ground the circuit.
Puzzling is your one cylinder miss, with steady vac readings?

[koates]

Hi Craig, hope you are all refreshed after your break. I have noted that some newer manufactured spark plugs are not very good. Why not clean the old plugs that you took out and refit them. Clean the threads in the heads where the plugs screw in. Regards, Kevin,

[petehoovie]

Welcome back, Craig...

[47topless]

[QUOTE=Terry,OH;2286051][B]Did you check for a vacuum leak on the vacuum line at the distributor and on the end at the intake manifold, where there is a special bolt connecting the vacuum line to the intake, the special bolt can break, or be loose or the banjo type fitting can be leaking on either side. The [/B]rubber tube to the vacuum wipers may be cracked, best to block the vacuum port at the point where the wiper tube connects to check. If your connecting to the wiper port on the special bolt with your vacuum gauge then the wiper rubber tube is not the problem.

You really need to do this.!

[Old Henry]

[QUOTE=47topless;2431395]

Originally Posted by Terry,OH

[B]Did you check for a vacuum leak on the vacuum line at the distributor and on the end at the intake manifold, where there is a special bolt connecting the vacuum line to the intake, the special bolt can break, or be loose or the banjo type fitting can be leaking on either side. The [/B]rubber tube to the vacuum wipers may be cracked, best to block the vacuum port at the point where the wiper tube connects to check. If your connecting to the wiper port on the special bolt with your vacuum gauge then the wiper rubber tube is not the problem.

You really need to do this.!

I did all that. No vacuum leaks.

[Doublepumper]

Read through most of this, but not all, so I may have missed some of the things you've tried. Might monitor the coil primary voltage, looking for a drop while the engine is running and accelerating. But, you ran a separate feed wire to the coil and things got worse, making me think there's possibly a grounding problem. May want to connect a wire to the dist. body and ground it directly to the battery ground to check that.
S'all I got...Good luck!

[47topless]

Checking for vacuum leaks is good but, as you know, the distributor requires a viable source of vacuum in order to operate correctly. Have you checked for obstruction in that vacuum source line? Are you sure the distributor is receiving sufficient vacuum?
Going back through the volume of past posts to this thread, I do not find any mention of that. If I missed it, I apologize for wasting your time here.
Good luck with your car and hope you're back on the road soon.
Phil

[ford38v8]

Craig, here’s an idea on a test for your distributor: Do your “miss at acceleration” test with and again without vacuum to compare the difference in running. Remember beforehand to adjust the damper brake to a very slight drag. You’ll need to remove the distributor to make that adjustment, but that’s where it should be set at anyway. It also requires that your leather brake is in good shape and well oiled, and the edge of your advanced disc is not pitted from rust, and weights are able to move freely.

[1942deluxe]

I did have the leather come loose on one distributor and it created problems.

[Brian]

Craig, you said; Vacuum test was quite low and bouncy suggesting late valve timing.
that statement is somewhat vague....late valve timing does not make the needle fluctuate....please study this chart; https://www.onallcylinders.com/2016/...auge-readings/

[motordr]

I would try the Bosch/VW 6 volt “blue” coil. Also if you have access to a Sun distributor machine to bench test your distributor. Are the points contacts clean, not oxidized?

[The Art Doctor]

I'd put the old worn out distributor back in and see if the problem goes away. That was the origin of it all, changing the distributor because of a worn lobe, correct? You said it was fine before, should be fine again with the old parts back in. If it is fine with the old parts then you know where your deficiency lies, in the reman distributor. Some old stock parts are not good, that's why they are still on the shelf, old returns of not good parts. If its still bad, which I'd doubt, I'd look internally for a stuck valve or worn camshaft by pulling the intake as that is easy to access and a relatively cheap gasket so you wont feel like you wasted one if you find nothing from the exercise.